/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.beam.sdk.util;

import org.apache.beam.sdk.annotations.Internal;

/**
 * An object for detecting illegal mutations.
 *
 * <p>The {@link AutoCloseable} aspect of this interface allows use in a try-with-resources style,
 * where the implementing class may choose to perform a final mutation check upon {@link #close()}.
 */
@Internal
public interface MutationDetector extends AutoCloseable {
  /** @throws IllegalMutationException if illegal mutations are detected. */
  void verifyUnmodified() throws IllegalMutationException;
}
